Heat-tolerant genes may spread through coral populations fast enough to give the marine creatures a tool to survive another 100 years of warming in our oceans.

Coral reefs are facing no shortage of threats including ocean acidification, overfishing, plastic pollution, and rising temperatures. Sea surface temperatures have been climbing on average for over a century, and ocean heat waves—which can trigger coral bleaching events—are becoming more common and severe. Scientists have long worried that as coral-killing spikes in temperature become more frequent, corals won’t have enough time to recover between bleaching events and will ultimately go extinct. But a new paper, published today in PLoS Genetics, suggests that corals might be able to adapt to another century of warming.

“Everybody knows if you take a present day coral and put it in a bucket with future [temperature] conditions, they tend to die,” says Mikhail Matz, an associate professor at the University of Texas–Austin and lead author on the new study. But given that the geographical range of corals spans many temperatures, Matz and his colleagues wondered if corals might be able to adapt as sea temperatures gradually increase.

The researchers already knew that members of at least one common species of coral on the Great Barrier Reef, Acropora millepora, possessed heat-tolerance genes. They wanted to investigate whether natural selection might take its course, spreading those heat-tolerant genes across the population and allowing corals to adapt as sea temperatures gradually increase.

The team built a model that took into account the coral’s genetic diversity and the distance that coral larvae travel before settling down, to predict how quickly heat-tolerant genes might spread. The model suggests that A. millepora has enough genetic diversity to survive another 20 to 50 generations—a timespan of 100 to 250 years.

Abstract

Can genetic adaptation in reef-building corals keep pace with the current rate of sea surface warming? Here we combine population genomics, biophysical modeling, and evolutionary simulations to predict future adaptation of the common coral Acropora millepora on the Great Barrier Reef (GBR). Genomics-derived migration rates were high (0.1–1% of immigrants per generation across half the latitudinal range of the GBR) and closely matched the biophysical model of larval dispersal. Both genetic and biophysical models indicated the prevalence of southward migration along the GBR that would facilitate the spread of heat-tolerant alleles to higher latitudes as the climate warms. We developed an individual-based metapopulation model of polygenic adaptation and parameterized it with population sizes and migration rates derived from the genomic analysis. We find that high migration rates do not disrupt local thermal adaptation, and that the resulting standing genetic variation should be sufficient to fuel rapid region-wide adaptation of A. millepora populations to gradual warming over the next 20–50 coral generations (100–250 years). Further adaptation based on novel mutations might also be possible, but this depends on the currently unknown genetic parameters underlying coral thermal tolerance and the rate of warming realized. Despite this capacity for adaptation, our model predicts that coral populations would become increasingly sensitive to random thermal fluctuations such as ENSO cycles or heat waves, which corresponds well with the recent increase in frequency of catastrophic coral bleaching events.

Author summary

Coral reefs worldwide are suffering high mortality from severe thermal stress episodes induced by acute ocean warming events. Under the current rate of warming, will corals be gone before the end of this century? Here we combine population genomics with biophysical and evolutionary modeling to investigate adaptive potential of a common reef-building coral from the Great Barrier Reef. To approach this task, we have developed a predictive model of polygenic adaptation in a system of multiple inter-connected populations that exist in a heterogeneous and changing environment. Applying this model to our coral species, we find that populations successfully adapt to diverse local temperatures along the range of the Great Barrier Reef despite high migrant exchange and should collectively harbor enough adaptive genetic variants to fuel region-wide thermal adaptation for another century and perhaps longer. In the same time, the model predicts that random thermal fluctuations will induce increasingly severe coral mortality episodes, which aligns well with observations over the last few decades.

““Everybody knows if you take a present day coral and put it in a bucket with future [temperature] conditions, they tend to die,”… “
Except, if you put a present day coral in a bucket of present day water and raise it gradually over the next 100 years, it may be just fine.
It ‘s that sudden shock that’ll kill ya’!

Yes. Every “future climate” in the models already exists in another location, often not that far away. And those locations sport thriving eco-systems that may or may not be significantly different, but are still alive.
Here in Central England we are still waiting for the Mediterranean climate we were promised. Perhaps its northward march has been halted somewhere in France, but nobody expects it to bring mass extinctions when/if it finally arrives. It certainly didn’t do in the past, unless you count Julius Caesar landing in Kent as part of a mass Roman extinction event. (What have the Romans ever done for us?…)

What future temperature conditions did they use? The next ice age, or red giant expansion that engulfs the Earth?
I’d go with hot. I don’t like sushi (my ancestors discovered fire).
Heck that’s my preferred may of preparing seafood. Headfirst into boiling water for about, 7 minutes/pound (less for larger lobsters). With drawn butter….

@ michael hart
“Perhaps its northward march has been halted somewhere in France”
Well, now we have ‘Brexit’ it wont be alowed passed border control,…we wont want any of that nasty foregn Mediterranean cilmate in britain

A model and unembarrassed claim to know future temperature conditions (based on other models) – more make believe science. This must stop. Models are hypotheses about how nature works, not evidence. They must be tested with real world observation and experiment. Till then they are just interesting or perhaps not so interesting theories. Academics really need to get back on track. And publishers should try and remember what their role is (I mean other than propaganda sales).

“including ocean acidification”
The oceans are not acid, nor are they becoming so.
“…if you take a present day coral and put it in a bucket with future [temperature] conditions, they tend to die,”
Buckets are not their natural habitat.

The Atlantic has a scary Great Barrier Reef coral story out, claiming that “half of all coral in the Great Barrier Reef has died,” and featuring quotes from Terry Hughes and activist UNC prof/blogger John Bruno, a/k/a “SeaMonster.”
When you read the actual Hughes paper, it does not say “half of all coral in the GBR has died.” It says, “In the northern, 700-km-long section of the Great Barrier Reef (from 9.5–14.5 °S), in which the heat exposure was the most extreme, 50.3% of the coral cover on reef crests was lost within eight months…” during 2016.
That was the El Nino, of course. So, what change during El Nino would cause reef crests in the western Pacific to be particularly impacted?
Water level, obviously. During El Niños the easterly trade winds weaken. That causes water in the tropical Pacific to “slosh east,” which causes a sharp fall in sea-level near Australia, uncovering coral on the reef crests. It’s presumably exposure to the air which kills coral on the reef crests in the western Pacific during El Niños.
WUWT has had coverage of Terry Hughes, the paper’s fear-mongering lead author, who was quoted in that misleading artlcle, before:https://wattsupwiththat.com/2017/08/26/an-ecologists-plea-to-dr-terry-hughes-the-public-needs-robust-science-regards-coral-bleaching-not-fearmongering/

Hi Dave,
I envy you! I lived in Australia a couple decades ago and dove the GBR a couple dozen times. Phenomenal! Tremendous. Unforgettable.
I am glad to hear it’s healthy. However, I wondered how you could get such different results – is it due to recovery? What was the scoring and sampling method? Is most of the bleaching on the outer shelf? That’s not really representative of the reef as a whole.
From the article:
“A section of reef that Mike Ball Dive Expeditions’ operations manager Craig Stephen is very familiar with.
“’It wasn’t until we got underwater that we could get a true picture of what percentage of reef was bleached,’ Craig said. ‘We expected the worst.'”
It puzzled me how anyone with Mike Ball could be surprised at the state of the reef if he is very familiar with it. Surely diving has continued, and the commercial operators would choose the healthiest spots, no?

Just yesterday while on an 8-hour drive up and down I-81, I heard on NPR that the GBR is dying, most of it is gone, and it won’t be coming back anytime soon! I just don’t know where they get these stories, it is like Whispering Down the Lane, starts out fairly innocuous and comes out the other end as a dire death of all corals and pure fiction!

Where do they get those stories from? “Scientists” from universities doing “studies” paid for with the tax dollars of those in OZ for the most part. Current theory is the GBR started forming about 500,000 years ago and has gone through quite drastic changes over that time. So the thing has survived the Holocene Optimum and last great glaciation and all of the temperature and sea level changes in that time. And yet we’re supposed to believe that a change of a degree or two is killing it off for good? Frankly it seems that sun block residue is a bigger threat.

It baffles the mind where this stuff comes from. As for sunblock, I am allergic to that gunk so the corals are safe from me. I am not convinced that sunblocks are safe to use anyway, a physical sun block like a shirt, hat, and even trousers/sarong work better. One field trip with sunburned hands and feet taught me a good lesson….

That’s what it is Pamela, I’ve dived and fished on reefs all along the West and East coasts, all my life, seen and heard enrless doom prophesies about the reef, since about mid-1970s, and all of the predictions have been complete rubbish, the reefs I have been to, have never looked better than now.
The bleaching events are just like the cyclones, they come and go, always very temporary impairment/degradation, with startlingly fast recoveries. Nay, over-recovery!
The truth is, that just like bushfires, the bleaching is actually conducive to a rapid and prolific re-colonisation and regrowth. The more a reef is disturbed and damaged, the more vibrant is the subsequent resulting coral cover and species diversity present. It makes room for far more coral types to settle, and their growth rate is incredible, like trees coming back after a fire.
If you want to see a really “happy” looking reef, just visit one that was smashed and dead just 3 years previously. It will make your head spin and eyes pop at how good it looks. It can not be described, you have to see it to realise the reef is insanely tough. NOTHING stops it.
What makes coral reef look really lacklustre is the lack of such disturbances. When that happens, the corals look old, colours less vibrant, and species diversity plumets sharply.Many coral types die.
It is the sames as seen in other mature “climax” communities, the species and vibrancy actually declines when it is “conserved” by a lack of severe damage to it.
Reefs LOVE disturbances, the more destructive the bettef, it is what renews them, just like a wild fire does the bush, the more danaging, the better and more breath-taking is the coral recovery. If you plow a field to bare dirt, come back in three years, what do you find? Plant regrowth.
The coral is the same, I have seen reefs with 90% coral cover, with three times ad many species, just 4 years after a major cyclone completely smashed it.
The Professors are all deviousliars, the grenies are all sick puppies who never tell the truth, the politicians are just crooks, on the make, and the media are the true filth, who enable the entire kleptocratic criminal rort process to continue, decade after decade.
Believe none of it.
The reef has never looked better than now, a massive disturbance just makes it healthier than you’ve ever seen it, and the fishing is, of course, incredible also.
40 years of endless doom BS from loonie JCU and U of QLD Professors, and there’s still no sign of the doom, nothing even unusual or new occurring at all.
But for sure, the JCU agenda-driven dog and poney show, and the State and Federal loonie gas-bags talking pure rubbish, and the greenie NGO flat out liars, and the ABC blatant fraudsters, will keep on claiming the reef is on its last gasp, and in another 40 years it will still be just as incredible as it was in 1971, and now in 2018.
No net-negative changes of any kind.

All corals, like all life, all die over time.
Clearly they are at the least teplacing themselves at the rate they die off.
The “coral reef is dead” meme is at least as stale and fact-free as the “polar bears/penguins/whatever are dying off” memes:
great for fund raising and click bait.
worthless for describing reality in an ethical manner.

Dave Burton,
” it does not say ‘half of all coral in the GBR has died.'”
Nor does this research say “corals adapting fast enough to withstand another century of climate change.” It has nothing to do with observed adaptions, and it’s about one species of coral, not “corals.”
There is no monopoly on the truth or the distortion of it.

Coral survived the end of the last ice age, where not only did temperatures increase, but sea levels increased by 400 feet. How do studies like this one make any sense, in the face of what earth has already proven? Let’s see…corals adapt to a changing earth…duh. Give me some money.

I agree with you John.
How long have corals been around? Many millions of years?
How many cycles of warmer and colder ocean temperatures have they endured, survived and thrived?
The answer: Beaucoup!
Enough to prove that this very-scary global warming story is just more of the usual warmist nonsense.

Corals of one kind or another have been around since at least the beginning of the Cambrian Period, ie 542 million years ago.
So they’ve survived all the climate change of the Phanerozoic Eon, from colder than now to much hotter.

@Chimp
All of the prior ‘corals’ in existence went extinct at the end of Permian extinction, they were very different in form and habit compared to modern corals.
The unrelated modern coral types initially developed around 240 mya. But yes, as a species they are incredibly tough and really impressive survivors. For perspective 15 million years ago the top of mount everest was over 1 km below the waves. But modern corals are 15 times older than the entire Himalayan mountain range. They have seen numerous unthinkable transformations of the entire earth and survved them all, including the global extinction of the dinos. 50 million years ago the Southern ocean didn’t even exist. In fact the entire Pacific ocean crust is younger than modern corals. They are older than the Indian ocean also.
They will easily out survive humans.

WX,
Modern corals aren’t completely different from their Cambrian ancestors. They descend from a group which was less common before the Permian extinction.
Also, you don’t mean “as a species”, but as a class, ie Anthozoa.
Like modern corals, even their most ancient ancestors frequently enjoyed the company of endobiotic symbionts.

@ Chimp
Thanks, but those were not modern corals. Modern corals are Scleractinia and they did not show up in the fossil record until 240 mya, and did not become common until the Pacific basin began to form 30 my later.https://en.m.wikipedia.org/wiki/Scleractinia
“Evolutionary History
There is little evidence on which to base a hypothesis about the origin of the scleractinians; plenty is known about modern species but very little about fossil specimens, which first appeared in the record in the Middle Triassic (240 million years ago).[1] It was not until 25 million years later that they became important reef builders, their success perhaps a result of teaming up with symbotic algae.[15] Nine of the sub-orders were in existence by the end of the Triassic and three more had appeared by the Jurassic (200 million years ago), with a further suborder appearing in the Middle Cretaceous (100 million years ago).[9] Some may have developed from a common ancestor, either an anemone-like coral without a skeleton, or a rugose coral. A rugose coral seems an unlikely common ancestor because these corals had calcite rather than aragonite skeletons, and the septa were arranged serially rather than cyclically. However, it may be that similarities of scleractinians to rugosans are due to a common non-skeletalized ancestor in the early Paleozoic. Alternatively, scleractinians may have developed from a Corallimorpharia-like ancestor. It seems that skeletogenesis may have been associated with the development of symbiosis and reef formation, and may have occurred on more than one occasion. …”https://en.m.wikipedia.org/wiki/Scleractinia
—–
The evolutionary origins of modern corals is actually indeterminate, prior to 240 mya, and it is not evident in fossil record that any corals at all survived the Permian.
Note the text above says their form may have developed, independently, more than once (i.e. but not survived into the Triassic).

The Medieval Warm Period was much warmer compared to the Modern Warm and the Roman Warm was warmer still, and before that, the Minoan was the warmest of all. Since the Minoan, our warm periods have become less warm. Corals all thrived happily in every warm time.

Terrestrial generics is more subtle and complicated then Mendel ever dreamed. We know now that mammalian genomes have “tiles”, set of genes whose expression can be triggered by environmental conditions, mostly in the next generation. Tiles contain adaptions to environments (high altitude, high heat, severe cold, etc.). It would be no surprise to find the same mechanism in corals, which have survived environments from hot house Earth to full-blown Ice Ages.

“Everybody knows if you take a present day coral and put it in a bucket with future [temperature] conditions, they tend to die,” says Mikhail Matz
“Everybody knows if you take a present day coral and put it in a bucket with future [temperature] conditions, they tend to die,” says Mikhail Matz
======???
Corals tend to die when placed in a bucket period. Regardless of temperature.
Never being exposed to double blind testing, climate science continues to discover that toads cause warts.

The thing almost never ever mentioned in these and other papers on coral mortality is that it is only near-surface/shallow-water reefs that are being affected by bleaching.
In reality, reefs are found in waters up to 200-300 feet deep — where the temperatures never will reach bleaching ranges. These deeper reefs “seed” re-growth of shallow reefs.
Some corals found at 410 feet on the Great Barrier Reef. Average water temp at 400 feet is about 15C.

hunter ==> Most coral research is done using SCUBA gear — and deep dives are harder, take longer, and require more skill. Because decent and ascent times are extended for deeper diving, most coral study diving is kept above 50-60 feet.
At the University of Puerto Rico’s Marine Science lab at La Pargeura we met young researchers who often spend 6 or more hours underwater a day….in water 20 feet or less…..
That much time in deep water can be grueling, at least in my experience.

Agreed. I’ve never seen coral bleaching on a wall dive on the outer face of the reef where it falls off into the abyss.
Bleaching occurs right at the surface in the tidal zone where the reef shelf’s. In this area the water tends to pool in the shallows and due to reduced circulation can become noticeably warmer than on the reef face.

@Ferd
Yes, the outer great barrier oceanward reefs stay cooler, the mid-lagoon reefs and embayed reefs are the ones that get hit hardest. The lagoon is typically less than 25 m depth, and currents are lower and the lagoon is as much as 150 km wide, to as little as 30 km wide in places. The outer reef currents are higher which keeps them cooler
But the bleaching always occurs when the seasonal winds are predominently north westerlies. South easterlies then to mix and stir the lagoon waters to keep them cooler, but the light humid hot NW winds prevent the usual mixing, so the surface heats, but lower lagoon remains cool enough to survive.
And it’s during El Nino that the hot NW wind geometry dominates the QLD coast. On top of this during El Nino the cyclones stay in Eastern coral sea and central Pacific, so no cloud or cyclone mixing of lagoon waters either.
It’s the stratfication from lack of mixing that kills them.

Coral reefs are found in abundance in the HOTTEST ocean waters on earth. It is cold water that limits their growth.
I defy anyone to name a single location with clean ocean water outside of a volcanic vent where it is too warm for coral to grow. The worry over coral and warming is due to ignorance.
I spent nearly 20 years living and sailing within a few hundred miles of the equator. I’ve seen plenty of bleached coral. No big deal. almost always it is species specific and soon repopulates.
Dead reefs however don’t come back. These are the ones covered with urchins and algae. These are the result of fishing and loss of water quality due to runoff.

Yes! Corals like hot water.
While the GBR began forming earlier, it took off during the unusually warm interglacial about 400,000 years ago, with higher sea levels and an approximately four degree C water temperature improvement.

The coral at Bikini atoll is in pristine condition and growing like a forest – no pollution.
The coral around Cuba is in pristine condition- they do not use pesticides.
5% of the world’s coral is protected and is in good condition.
I think the above illustrates what the real enemy of coral is and it certainly is not climate change.

I spent nearly 2 months this winter snorkelling in 3 oceans, (Pacific, Atlantic & Indian) in fairly shallow warm waters between 10 and15 degrees N tropical in 5 countries. I didn’t come across one area of any dead or bleaching corals. When asking guides and tour boat operators, they say they rarely see any naturally damaged coral, but a fair bit of damaged corals from improper fishing, anchors and deliberate sand salvaging in adjacent coral areas. A few indicated what some say here, is that it is mainly a few larger areas like the GBR when El Nino conditions cause rapidly changing ocean temps and levels, and that they mainly recover as soon as the specific condition changes. Some blamed the CAGW meme for everything, but it sounded like the same misinformation we get every day about trying to weave a narrative that fits an agenda. I saw absolutely nothing anywhere other than some garbage and pollution, or manmade destruction. Some of the video’s that are replayed over and over of the same dead or bleached reefs is a similar tactic as the forestry eco-warriers showing the same picture of an old clear-cut for the next 20 years. Let’s concentrate on reducing the obvious pollution and garbage which really is gross and detrimental, and I am sure the coral reefs will do just fine.

Wasn’t me. I suppose I should apply sunscreen, but never have even once in my life. Rather take my chances with the UV and excess Vitamin D. My Dr. (and the science) would probably strongly disagree.
But at a quantum level, I suppose the act of observing the coral may have some effect, but may be hard to say whether it is good or bad. I think I could sense the coral saying they were so glad to see me, admiring their beauty, like a fine woman.

Since people started preventing the sun from reaching their skin, we have had an unfortunate incidence of low levels of Vit D. Apparently D is an important precursor to important hormones in our bodies and not enough of it is bad. The incidence of melanomas has not increased but someone is raking in a lot of money selling sunblocks. I prefer to take my chances on developing a melanoma instead of causing a real problem by not having enough D in my body. The sun is our friend, to be luxuriated in on nice days!

Coral are notorious suckers for flattery. It’s their small brains and great beauty.
Dunno your age of course, but honestly, I recommend sun block, especially in the tropics or high altitude. However, only when in the air and not water. UV does indeed penetrate water, but the ocean isn’t like a swimming pool.
The problem is that en route to your dive point, you’ll be wearing sunscreen, and can’t really be expected to shower before diving. So maybe your approach is better. Just take every opportunity to stay out of direct sunlight and wear a high SPF hat and clothes. Maybe zinc on the nose.

Physical sun blocks are far preferable to lotion blockers. Everyone should know their own tolerance to sun before they start to crisp. Hats, lightweight shirts or coverups are much better methods to avoid sunburn. Chimp is correct.

Pamela.
I went without sunscreen for most of 67 years and have had skin cancer on my arm and face.
IMO it has a place. I’d strongly recommend it for babies and children in the sun. We now have Vitamin enriched foods. Teenagers who want tans may pay for it later with skin cancer.
Science of course isn’t settled, but IMO the risk justifies judicious use of sunscreen.
But hats and long sleeved garments are good ideas. Just try to get teenagers to wear them, inviting ridicule.

Chimp,
I also went without sunscreen, we all waited for the pool to open on Memorial Day then arrived with our baby oil and towels and lay in the sun for most of the day, perfecting our “base.” I would look like a boiled lobster at school. I have been fortunate, have never sprouted a skin cancer, and I take good care of my skin otherwise, so look 20 years younger than I actually am, as an aging Boomer.
Then sunscreen came along, first Paba, then the other chemicals, and I started covering up and slathering my skin with the stuff. I cultivated a pallid complexion for a few years, and that is really difficult when working in the field in south Florida and the Caribbean.
The pallid stage ended when my Vit D deficiency was so bad I had to have three loading dose sequences over six months. Now I cover up, use zinc oxide, and keep track of how long I have been out in the sun. I have fair skin and burn easily so I always have a hat and shirt. Men are much more susceptible to skin cancers than women, which is unfortunate, so they really need to cover up more.
Children and babies should never be allowed to bake in the sun. Tanning beds are cancer machines! But try warning teens to be careful. Even pointing out that tans only became popular because the wealthy began playing sports and a tan no longer was a sign that the tanned was a poor laborer.

Indeed. My father had skin cancer on his neck from riding the tractor day in and day for 60 years in the prairie Sun before the era of the covered cab. Gives a whole new meaning to the word ‘redneck’. I should pay more attention to that and I did…wearing a Panama hat and long sleeve shirt and towel over my legs while on the ocean and water enroute and anchored to the dive/snorkelling sites. Plus a lot of the catamaran dive boats are covered, for that very reason. The younger folk were turning into lobsters who basked in the open sunlight, but then on dry land, I go and lay in the Sun soaking in the glorious Thai or Costa Rican Sun, but only until I feel a nice glow. Or maybe that was the rum…life in the tropics in nice.
Just for fun, I googled the sunscreen lotion issue with corals, and while I thought you were maybe teasing a bit about the pollution effects of sunscreen, I see that at 62 parts per trillion, it can become an issue for coral reefs. Learn something new every day here.http://time.com/4080985/sunscreen-coral-reefs/

Yeah, this blog is great, thanks to the collective knowledge, wisdom and varied experience of so many commenters. Thanks to our host and moderators!
I learned the hard way to keep a towel over my legs when South Pacific ocean “kayaking” in one of those plastic thingees without leg cover. I knew that the sunscreen would wash off, but idiotically hoped that enough would remain to keep me somewhat protected. More fool I!

Huh. I read this as scientists saying, “Um, duh. Of course the coral is going to die if you suddenly throw it in a bucket of water that is several degrees hotter than the water it was just in. Let’s see what might happen in the REAL world, since any shift would likely be gradual.”
Yes, it is a model, but it sounds like they actually tried to do a proper one. There is some crap in there, especially at the end of the abstract, but the premise itself is actually reasonable. It is amazing that the paper got published, seeing as it is acknowledging that animals are capable of adapting to environmental change. The writers should probably watch their backs.

AllyKat,
“Yes, it is a model, but it sounds like they actually tried to do a proper one.”
What’s a “proper “model?
I don’t suppose there’s any connection between it being a “proper” model and the fact that you think it is something mainstream science would’t want published? Hate to tell you, but it’s no such thing. Heck, any good alarmist worth her weight would twist this into a story where a bleaching event leads to massive takeover by a few corals with the genes allowing temperature flexibility. and resilience, and those that are able to grow super fast between bleaching events. Reefs can recover structurally from great damage, but the question is how their communities might change due to severe, repeated bleaching events.
This is an interesting study.http://www.pnas.org/content/97/10/5297.full
“Amazing that the paper got published, seeing as it is acknowledging that animals are capable of adapting to environmental change.”
Oh, please! What a cliche. Science is out to silence not only the skeptics, but any research that they think supports the skeptic case.
What kind of scientist are you, AllyKat?

The daily range of pH on the shallower parts of the GBR is between 9.4 in late afternoon and 7.5 just before dawn; and, as this is presumably related to diurnal temperature change, it suggests the reef can take care of itself, as it has done since it began its present phase of existence some 7000 years ago … And don’t forget the symbionts which are very adept at temperature avoidance

Petroalbion,
The fact that there’s diurnal fluctuation in the environment doesn’t mean that the community can withstand being without one end of the range if important processes are restricted to one end or another. As an analogy, plants survive day and night, but they aren’t good at surviving permanent dark.
What do you mean by symbionts adept at temperature avoidance?

Has no one noticed that the Great Barrier Reef (GBR) is oriented roughly North–South?
And ‘the reef’ does not stop at the northern tip of Queensland, it extends to all the reefs around Papua, all the way to its northern coast line and into the NORTHERN HEMISPHERE.
Have a look at a freakin’ SAT image of the area if you think not. Papua’s coast is also sourrounded by prolific ultra divetse coral reefs.
In other words, there is an interconnected patch-work of coral reefs all the way from Japan, Marianas to Phillipines, to Papua, to just east of Brusbane in Morton Bay, plus around Western Australia as well. Plantonic corald can and do migrate, very rapidly, as local conditions vary. Eqatorial heat adapted corals will seed the GBR. Coral actually prefers equatorial warmth, there are literally SIX TIMES MORE coral species at the EQUATOR, than found on the GBR!
The GBR is NOT the global repository of coral species—it’s not even close to being that. The actual repisitory is in the hottest water on eatth!
Because that’s what corals PREFER, they THRIVE in hotter waters.
GBR corals however are of course more COOL WATER ADAPTED species. Get it yet?
The only place coral reef is actually being totally demolished and eliminated is in the South China Sea, but greenies love Communists, so think thats fine, such is their abject stupor.
Plus there is a gyre-driven north to south “East Australian Current”—did no one see ‘Finding Nemo’, little dudes?
Apparrently not—well you should!
So does anyone seriously wonder, or expect the world to believe that planktonic phase coral larve is reliant upon gene selection to ‘survive’ the almost undetectable slight warming? As though corals are immobile—no they are not!
How absurd this GBR doom farce is.
Another thing the dishonest alarmists never want to mention is that heavy rain also causes coral reefs to bleach on the GBR. Oh noes, we must combat the clouds too now.
Plus they always want to pretend bleaching was only discovered around or just before 1998. Rubbish! It was taught to us during the mid-1980s and causation was already fairly well understood, and it was a prosaic long-term periodic reef phenomena.
They also don’t want people to fully realise that the reason why the reef doesn’t extend further southwards past Brisbane, is because the cold water down that far KILLS THE GREAT BARRIER REEF.
The planktonic larve that re-seeds the entire reef, EVERY YEAR, dies when the water is that COLD.
This whole topic of ‘threat’ to the GBR is a FAKE, a canard to hype the fake cagw hype, even further. This whole GBR doon FRAUD is just a shameless as the ACID oceans HOAX.
Stop falling for their totally fake hysterical lies.
The ONLY reason there’s so much absurd alarmism noise and laughable pseudo-‘research’ is because our Communist Government is throwing hundreds of millions of our tax dollars, frow our wallets, at the bludging alarmists’ pockets.
Go figure.

Sediment cores show crown of thorns is a periodic pest, like locusts, or mice plagues on land. They eat themselves out of food, due, and the coral grows back as though nothing happened.
Another nob-event, invariably reported with overtones of impending doom, and ibsinuatiobs humans sonehow did it.
The sediments say no, completely normal.

Which cites the 2016 event, and as pointed out up the page bt witnesses, actually produced less than 5% total coral cover loss, and that has already recovered.
i.e. just another inconsequential bleaching, like the many thousands before it.
But ABC can’t help itself from fluffing-up sone baseless hysteria over yet another hyped nothing that was going to end the world as we know it.
NOT.

Dontcha love this bit-
“The sample, taken from a depth of 1,170 metres, identified a remarkable cold-water coral community of living and fossil cold-water coral species, gorgonian sea whips, bamboo corals, molluscs and stalked barnacles.
Scientists believe the discovery of the undersea landslide and its vast debris field in the deep Great Barrier Reef reveal a far more complex landscape than previously known.
More seabed mapping and sampling is required to assess the tsunami hazard to the Queensland coast posed by underwater landslides.”
Trust us deplorables, if the global warmening and bleaching don’t get ya the landslides and tsunamis will.

Why is it that the people that make such claims avoid answering one simple question? If CO2 raises global temperatures as much as they claim (2.5°C per 50 ppm), then why wasn’t the Earths temperature 300°C some 500 million years ago when CO2 was 6000+ ppm?

” Sea surface temperatures have been climbing on average for over a century, and ocean heat waves—which can trigger coral bleaching events—are becoming more common and severe.” Is there any evidence to support this?

“Is there any evidence to support this?”
Well 97% of marine biologists on the public drip studying coral bleaching surveyed say it’s so. The other 3% were on sick leave with the flu at the time which is well within 5% standard error.

For permission, contact us. See the About>Contact menu under the header.

All rights reserved worldwide.

Some material from contributors may contain additional copyrights of their respective company or organization.

We use cookies to ensure that we give you the best experience on WUWT. If you continue to use this site we will assume that you are happy with it. This notice is required by recently enacted EU GDPR rules, and since WUWT is a globally read website, we need to keep the bureaucrats off our case!
Cookie Policy